1. Field of the Invention
This invention relates to a circular catalytic converter sensor connector for connection between an internal printed circuit board and terminals in a compact configuration.
2. Description of the Prior Art
Catalytic converter sensors, commonly called lambda probes, are usually attached to the housing of a catalyzer and project a sensor through a hole in the housing to measure various parameters of the exhaust gases. This hole in the catalyzer structure not only affects the mechanical integrity thereof but also produces a risk of gas leakage through the sensor hole. For correct functioning of the catalyzer, this gas leakage should be avoided. The size of the probe hole must therefore be kept to a minimum, as a small hole is easier to seal and has little effect on the mechanical integrity of the catalyzer housing.
Although reference above is made to measurement of exhaust gases in a catalyzer, the above remarks are often true in many other technical domains, that is to say, where one is measuring parameters of a liquid or gas within a container.
The probe usually comprises a printed circuit board which is partially exposed in the exhaust gas part of the catalyzer and partially within a connector attached to the catalyzer housing, whereby terminals in the connector make electrical contact between the circuit traces on the printed circuit board to external conducting wires. The printed circuit board serves to electronically process the measurement signals of the probe, and due to the high temperatures, the board is made from a material such as ceramic that can withstand high temperature. The boards are made by pre-cutting out of a large ceramic board the individual boards with a laser, the boards then broken off along the laser trace lines. One of the problems associated to this procedure is that the ceramic boards have sharp edges that would damage electrical contacts of a connector when inserted between the contacts.
In the prior art the plurality of terminals, for example eight terminals, are disposed in two rows, one on either side of the printed circuit board. The terminals, however, require far more width than the spacing of circuit traces on the printed circuit board because of the practicable manufacturable size and strength of the terminals that is desired. The diameter of the sensor connector must therefore be large enough to accommodate the rows of terminals and the walls separating the terminals. It is desirable to make the sensor connector circular because the circular hole in the catalyzer structure that mates therewith, can be manufactured easily with great precision in order to provide the best sealing properties. This means that the terminals disposed in rows as found in the prior art, does not effectively use the volume of the connector, especially towards the periphery, therefore requiring a large diameter connector.